JPH0431611B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a satellite receiver that receives and demodulates signals transmitted from a broadcasting satellite.

[Conventional Example] In recent years, stereo broadcasts and the like transmitted from broadcasting satellites have come to be received even in ordinary homes.
Particularly in the United States, reception of satellite broadcasting has become commonplace.

By the way, this satellite broadcasting includes monaural broadcasting, stereo broadcasting of various systems, etc., and the satellite receiver is equipped with a switch etc. for receiving the broadcasting in monaural mode and various stereoscopic modes. For example, in a satellite receiver that receives stereo audio signals, select the two channels of hand voice signals transmitted from the broadcasting satellite, and select "L".
ch., "R" ch. signals and reproduces a stereo audio signal.

[Problems to be solved by the invention] On the other hand, in recent movie theaters, etc., it has become possible for viewers to hear sounds from various directions, so it is difficult for viewers to hear sounds with a sense of realism. It is becoming possible to do this. In this method, for example, speakers are placed in front and behind a viewer, and the sound field is controlled so that the viewer can hear sound not only from the front but also from the rear, thereby performing surround playback. This sound field control is realized using a surround processor or the like.

The present invention has been made in view of the above points, and its purpose is to provide a novel satellite receiver that can reproduce surround sound using at least two channels of surround encoded signals transmitted from a broadcasting satellite. There is a particular thing.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a satellite receiver that receives signals transmitted from a broadcasting satellite and demodulates video and audio signals, which demodulates the audio signals. At the time of demodulating the audio signal, the stereo When switching to a mode or the like, the surround decoder is controlled to output a signal for surround reproduction.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

In the figure, signals of multiple channels transmitted from a broadcasting satellite 1 are received by an antenna 2. This signal is transmitted to the down converter amplifier 2a of antenna 2.
The signal is converted into a first intermediate frequency signal and input to the satellite receiver 3. Of the first intermediate frequency signal, the video signal and audio signal of the desired channel are demodulated in the amplifier circuit 4, frequency conversion circuit 5, intermediate frequency amplification circuit 6, detection circuit 7, etc. in the same manner as in the prior art. Here, for example, when stereo is being received, the audio signal passes through the audio subcarrier amplifier circuit 8, and then is subjected to, for example, "L+R modulation" in the first frequency conversion circuit 9.
The second frequency conversion circuit 12 converts the signal into an "L-R modulation" signal and demodulates it in the intermediate frequency amplification circuit 10 and the detection circuit 11. It is demodulated by Note that these frequency conversion circuits 5, 9, 12
The frequency conversion in is controlled by the microcomputer (CPU) 15 of the control circuit in the same manner as in the conventional art based on a channel selection switch (not shown) or the like.
This CPU 15 is equipped with a memory RAM 15a in which information etc. for switching are stored.

"L+R" and "L-" obtained with the above circuit
Both the "R" signals are input to the matrix decoder 16, and the "L+R" signals are input to the multiplex decoder 17. “L+R” and “L
-R'' signals are obtained and inputted to the mode switching means 18. This mode switching means 18 is, for example, an electronic switch, and is operated in conjunction with switching of the channel selection switch during reception. The mode switching means 18 includes
Two sets of changeover switches 19 and 20 are provided,
Monaural terminals 19a, 20a, disk lead terminals 19b, 20b, matrix terminal 1, respectively.
9c, 20c, MPX terminals 19d, 20d, external input terminals 19e, 20e, and common terminals 19f, 20f connected to these terminals. By switching the mode switching means 18, signals of "L" and "R" channels, which are stereo audio signals, are obtained.
In addition to being output from the conventional stereo terminals 23 and 23, "L" and "R" channel signals are input to the surround decoder 22. Furthermore, audio signals (external signals) from, for example, a VTR, video disc, etc., are inputted to the external input terminals 19e, 20e from external input terminals 21, 21. The "L'" ch. signal for surround reproduction from the surround decoder 22 The "R'" ch. signal is outputted from the surround output terminals 24, 24 for rear speakers. Therefore, in the case of surround playback, the audio signal output from the satellite receiver 3 is
In the case of normal stereo, "L" and "R" ch. signals and "L'" and "R'" ch. signals are output.

Next, the operation of the satellite receiver having the above configuration will be explained.

First, a channel selection switch or the like of the satellite receiver 3 is operated to receive a stereo broadcast from the broadcasting satellite 1. Then, the mode switching means 18 is activated in conjunction with the operation of the channel selection switch or the like. As a result, the audio signals of the two channels of stereo broadcasting received under the control of the CPU 15 are passed through the audio subcarrier amplifier circuit 8 to the frequency conversion circuits 9 and 12, and the intermediate frequency amplifier circuits 10 and 1.
3. Demodulated by the detection circuits 11 and 14, “L+
"R" and "LR" signals are obtained. Based on the "L+R" and "LR" signals obtained in this way, "L" and "R" ch. The signals of "L'" and "R'" channels, which are output from the stereo terminal 23 and are further controlled by the CPU 15, are outputted from the stereo terminal 23 for the speakers placed in the front, and then delayed, for example, from the surround decoder 22, which is placed behind the viewer. Surround playback terminal 24 for the speakers to be used,
It is output from 24. Therefore, when the received stereo broadcast is reproduced in surround, "L", "R",
“L′” and “R′” ch. signals are output, and by outputting those signals from speakers placed in the front and rear, viewers can hear extremely realistic sound. can.

On the other hand, when the satellite receiver 3 is set to a monaural mode in which the satellite receiver 3 receives, for example, a normal broadcast program, the surround decoder 22
It is controlled by the CPU 15 so that it does not operate. As a result, the satellite receiver 3 outputs a monaural audio signal.

Furthermore, when the satellite receiver 3 is set to a mode for receiving surround encoded MPX signals, the CPU 15 controls the surround decoder 22 using the pilot signal output from the multiplex decoder 17, Obtain a signal for surround reproduction of the audio signal of the received signal. Further, when an audio signal from a VTR device or the like recorded as a surround encoded signal is input as an external input, when a channel selection switch or the like is set to the external input, the mode switching means 18 switches to the external input terminal 19e, 20e
can be switched to the side. Thereby, the CPU 15 obtains a signal for surround reproduction of the input audio signal that controls the surround decoder 22.

[Effects of the Invention] As explained above, since the satellite receiver is provided with a surround decoder for surround playback, surround encoded stereo broadcasts of satellite broadcasting, etc. can be played back in surround.
You can get realistic sound. Therefore, the satellite receiver can also be used as a new media.

[Brief explanation of drawings]

The figure is a schematic circuit block diagram of a satellite receiver showing one embodiment of the present invention. In the figure, 1 is a broadcasting satellite, 2 is an antenna and down converter amplifier, 3 is a satellite receiver,
4 is an amplifier circuit, 5, 9, 12 are frequency conversion and local oscillation circuits, 6, 10, 13 are intermediate frequency amplifier circuits, 7, 11, 14 are detection circuits, 8 is an audio subcarrier amplifier circuit, 15 is a control circuit (CPU), 16
17 is a matrix decoder, 17 is a multiplex decoder, 18 is a stereo mode switching means, 21 is an external input terminal, 22 is a surround decoder, 23 is a stereo terminal, and 24 is a surround output terminal.

Claims (1)

[Claims] 1. In a satellite receiver that demodulates video and audio signals transmitted from a broadcasting satellite, when the audio signal is demodulated, a signal for surround playback is output based on the demodulated audio signal. A surround decoder and an output terminal for outputting a signal obtained by the surround decoder are provided, and when switching to stereo mode when demodulating the audio signal, a signal for controlling the surround decoder to reproduce surround sound is provided. A satellite receiver characterized in that it outputs.